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<title>IsByRef() - Syntax &amp; Usage | AutoHotkey</title>
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<h1>IsByRef() <span class="ver">[v1.1.01+]</span></h1>

<p>Returns a non-zero number if the specified <a href="../Functions.htm#ByRef">ByRef parameter</a> was supplied with a variable.</p>

<pre class="Syntax">TrueOrFalse := <span class="func">IsByRef</span>(ParameterVar)</pre>
<h2>Parameters</h2>
<dl>

  <dt>ParameterVar</dt>
  <dd><p>A reference to the variable. For example: <code>IsByRef(MyParameter)</code>.</p></dd>

</dl>

<h2>Return Value</h2>
<p>This function returns 1 if <em>ParameterVar</em> is a <a href="../Functions.htm#ByRef">ByRef parameter</a> and the caller supplied a variable; or 0 if <em>ParameterVar</em> is any other kind of variable.</p>

<h2>Related</h2>
<p><a href="../Functions.htm#ByRef">ByRef parameters</a></p>
<h2>Examples</h2>
<div class="ex" id="ExBasic">
<p><a href="#ExBasic">#1</a></p>
<pre>MsgBox, % Function(MyVar)

Function(ByRef Param)
{
    return IsByRef(Param)
}</pre>
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